Spider-Mite Control in Australia

How to identify, treat & prevent two-spotted mites before they wreck your plants

What Are Spider Mites?

Spider mites are sap-sucking arachnids (not insects) that thrive in warm, dry conditions. The two-spotted spider mite is the most common culprit in Aussie veggie patches, houseplant jungles and hydro grows. Left unchecked they:

• Pierce leaf cells, causing pale “speckling” or bronzing
  
• Spin fine webbing that shields colonies and eggs
  
• Reproduce lightning-fast – a full generation in as little as seven days at 28 °C
  

How to Quickly Tell If It’s Spider Mites

Not all leaf damage is caused by spider mites, and treating the wrong pest can waste time and stress your plants. Use this quick guide to narrow it down:

• Fine speckling on leaves + faint webbing (especially underneath):
   Very likely spider mites.
  

• Bronzing or silvery leaves with little or no webbing:
   Could be another type of mite, such as russet mites.
  

• Curled or distorted new growth without webbing:
  Often aphids, thrips, or a nutrient issue rather than spider mites.

A simple check is to gently tap an affected leaf over a white piece of paper. If you see tiny moving dots (often red, brown, or pale), mites are likely the cause.

Correct identification is important, as spider mites respond best to repeated, targeted treatments rather than one-off sprays.

If you’d like a deeper visual breakdown of life stages, lookalike pests and close-up comparison photos, see our detailed Spider Mite Identification Australia Guide.

How to Identify Damage?

1. Visual check – Look for pinpoint yellow or white specks that coalesce into bronzed patches.
   
2. Paper test – Tap a suspect leaf over white paper; look for tiny moving dots the size of ground pepper.
   
3. Webbing – Silky threads at leaf axils or undersides signal an established infestation.
   
4. Magnify – A 10× loupe reveals oval bodies with two dark flanks (the “two spots”).
   

Spider Mites in Lawns

While spider mites are often associated with ornamentals and vegetables, they can also affect turf — particularly during hot, dry periods.

In lawns, damage typically appears as:

• Pale, bleached or bronze patches
• Fine stippling on individual blades
• Irregular or sometimes ring-shaped areas of thinning grass
• Subtle webbing close to the soil surface in heavy infestations

Spider mites thrive in dry, dusty conditions. Lawns under drought stress are particularly vulnerable.

Improving irrigation consistency can significantly reduce pressure. Deep watering that reduces plant stress and increases surface humidity makes conditions less favourable for mite reproduction.

If lawn patches worsen during extended dry heat and improve with cooler, moist conditions, spider mites may be contributing to the problem.

Early detection and environmental adjustment are often enough to prevent escalation.

Plants Commonly Affected by Spider Mites

Spider mites feed on a wide range of plants. In Australian gardens, they are frequently found on:

Vegetables

• Tomatoes
• Cucumbers
• Beans and peas
• Eggplant
• Capsicum
• Potatoes

Fruit Crops

• Strawberries
• Raspberries
• Citrus
• Apples and pears

Ornamentals

• Roses
• Azaleas
• Hibiscus
• Indoor foliage plants

If you’re seeing fine stippling or leaf bronzing on these plants during warm, dry weather, spider mites are a strong possibility.

Knowing which plants are commonly targeted helps narrow down diagnosis quickly.

Spider-Mite Life-Cycle & Seasonal Timing

Aussie outbreaks spike in late spring and again in mid-summer when temps exceed 25 °C and humidity dips under 40 %. Indoor grows with powerful LED lights can see year-round pressure.

Physically Remove as Many Mites as Possible

Before applying any treatment, reduce numbers as much as you can through physical removal. This step alone can dramatically improve results.

• Rinse plants thoroughly with a firm spray of water, focusing on the undersides of leaves where mites gather.
• Wipe leaves by hand using a soft cloth or sponge, especially if webbing is present.
• Remove heavily infested leaves and dispose of them in the bin (not compost).

Webbing can prevent sprays from reaching mites properly. Clearing it first ensures treatments make direct contact, which is essential for control.

Skipping this step is one of the most common reasons spider mite treatments fail.

Prevention Tips

• Boost humidity – Group plants, mist lightly or run a humidifier.
  
• Improve airflow – Clip dense foliage and install an oscillating fan.
  
• Leaf hygiene – Wipe dust with a damp cloth or use TurboWash Leaf Cleaner to remove residues that shelter eggs.
  
• Regular scouting – Inspect undersides weekly with a loupe. Early detection beats any spray.
  

Why Increasing Humidity Helps Control Spider Mites

Spider mites thrive in hot, dry conditions. Raising humidity makes their environment less favourable and can slow their life cycle.

Practical ways to increase humidity around plants include:

• Lightly misting the undersides of leaves (early morning is best)
• Placing plants closer together to create a humid microclimate
• Using trays of water near indoor plants or in greenhouses
• Damping down greenhouse floors on hot days

While humidity alone won’t eliminate an infestation, it can significantly reduce how fast spider mites multiply and support other control methods.

Why Some Sprays Make Spider Mites Worse

Spider mites reproduce very quickly and can develop resistance if the same treatment is used repeatedly.

Some broad-spectrum insecticides are also ineffective against mites, and can make infestations worse by:

• Killing beneficial insects that naturally keep mites in check
• Leaving spider mites unaffected, allowing populations to rebound faster

For best results:

• Use products specifically labelled for mites
• Follow repeat application instructions carefully
• Avoid rotating randomly between unrelated sprays

A planned, targeted approach is far more effective than switching products after each application.

Using Predatory Mites for Spider Mite Control

Predatory mites are beneficial insects that feed on spider mites and their eggs. They work best when infestations are detected early.

Key points to know:

• They are most effective before heavy webbing develops
• Broad-spectrum sprays should be avoided before and after release
• Best suited to greenhouses, indoor plants, or controlled environments

Predatory mites are a useful option for gardeners looking to reduce chemical use, but they need the right conditions to succeed.

Choosing the Right Predatory Mite

Not all predatory mites behave the same way.

Two commonly used biological controls in Australia are:

Neoseiulus californicus

• Performs well across a wider temperature and humidity range
• Suitable for preventative releases
• Ideal when spider mite pressure is low but conditions are favourable

Phytoseiulus persimilis

• Highly specialised spider mite predator
• Best used when active infestations are already present
• Works rapidly when introduced early

The key is timing.

Do not wait until heavy webbing and widespread bronzing appear before introducing predators. Biological control works best when populations are still manageable.

Early intervention prevents outbreaks from reaching explosive levels.

Treatment Options & Product Picks

A. Organic & Low-Impact

B. Conventional Contact Sprays

C. Systemic & Residual Protection

7-Step Action Plan

1. Isolate affected plants to stop migration.
   
2. Mechanical clean-up – Blast undersides with water, then apply Green Cleaner at 15 ml/L to strip webs.
   
3. Knock-down spray – Follow immediately with Kendon Pyrethrum (mix 10 ml/L). Repeat 3 days later.
   
4. Leaf shield – After knock-down, apply Broad Blue Protect RTU evenly to tops & bottoms of leaves.
   
5. Soil & crevice dusting – Puff Diatomaceous Earth on pot rims and media surface.
   
6. Monitor & re-treat – Scout twice weekly. If mites persist, rotate to Kill-A-Mite (ornamental use) or a second botanical spray for edibles.
   
7. Long-term hygiene – Maintain airflow, humidity above 45 % and wipe leaves fortnightly with TurboWash.
   

Tip: Always spray at dusk or under low light to prevent leaf burn and give solutions time to work overnight.

Common Spider Mite Control Mistakes

• Treating once and stopping – spider mites require repeat applications
• Spraying only the top of leaves
• Not isolating infested plants
• Ignoring hot, dry conditions that favour re-infestation

Wettable Sulphur (Advanced Option)

Wettable sulphur can suppress spider mite populations when applied correctly.

It works by disrupting mite feeding and reproduction and can also assist in managing certain fungal issues.

However, there are important considerations:

• Only use products labelled for spider mite control
• Do not apply during extreme heat
• Avoid combining with oil sprays
• Follow all label directions carefully

Wettable sulphur is not the same as lime sulphur. The two products serve different purposes and should not be used interchangeably.

As with all treatments, sulphur should be part of an integrated approach — not a standalone solution.

How Spider Mites Re-Enter the Garden

Spider mite control isn’t just about killing active populations — it’s about preventing reinfestation.

Spider mites can spread through:

• Wind currents
• Clothing and gardening gloves
• Pruning tools
• Movement of infested plants
• Shared greenhouse environments

Eggs can overwinter on plant material, pots and surrounding debris. When temperatures rise in spring, populations rebuild rapidly.

To reduce carryover between seasons:

• Remove heavily infested plant debris
• Clean greenhouse benches and growing areas
• Wash reused pots before planting
• Monitor susceptible plants early in the season

Breaking the cycle early each year makes long-term control significantly easier.

FAQs

Will one spray eliminate spider mites?

Rarely. Females lay eggs daily, so plan for at least two follow-up treatments five to seven days apart.

Can I use these products on edible crops?

Diatomaceous Earth, Zero Tolerance and Green Cleaner are ideal for herbs & veggies when used per label. Kill-A-Mite is for ornamental plants only.

Are spider mites resistant to pyrethrum?

Resistance is possible with repeated single-chem sprays. Rotate modes of action (e.g., botanical → pyrethrum → systemic) and integrate cultural controls.

Do I need to treat the soil?

Spider mites live mostly on foliage, but dusting the pot rim and media with Diatomaceous Earth helps stop migrations and emerging adults.

Does neem oil work on spider mites?

Yes, when applied thoroughly and repeatedly. Coverage of leaf undersides is essential.

How often should treatments be repeated?

Most treatments require reapplication every 5–7 days until activity stops.

Can I treat edible plants?

Many treatments are safe for edible plants when label directions are followed. Always observe withholding periods.

Why do spider mites keep coming back?

Re-infestation often comes from nearby plants, dry conditions, or incomplete treatment coverage.

Should I isolate infested plants?

Yes. Isolating affected plants helps prevent mites spreading to healthy ones.

Final Word

Spider mites spread fast but you can beat them with sharp eyes, the right products and a tight schedule. Keep this guide handy, stock up on the treatments above, and reclaim your garden’s health.

Need more pest solutions? Explore the full Spider Mite Treatment collection or email us for tailored advice.

Happy growing!

About the Author